A little screengrab of my recent storyboarding- not by any means a great drawing, but you can see how I like to work- usually super loose to start with. I'm using flash mainly because I love the way its brush tool behaves- crisp and responsive, as close as I can get to my favourite real drawing tool, brush and ink. Flash also allows for very easy fills of colour, just one click and your character's flooded with colour. Coupled with the ability to work on a timeline and flip your drawings, it becomes an awesome boarding tool.
I use colour if it will help clarify the image to the viewer (and also because the perfectionist in me won't quit) -but in truth storyboarding is about working fast , intuitively, and not getting hung up on detail- genreally I try to hit somewhere in between.
That said, I'm desperate to get my hands mucky with some oil paints this weekend.
Have a good one, folks!